Sound-producing device.



PATENTED APR. 25, 1905.

R. HOPE-JONES.

SOUND PRODUCING DEVICE.

APPLICATION FILED NOV.6,1903.

2 SHEETS-BHEBT 1.

Inventor Robert Hope-fines By flttjy.

WLtncsscs.

PATENTED APR. 25, 1905.

R. HOPE-JONES.

SOUND PRODUCING DEVICE.

APPLICATION FILED NOV.6,1903.

2 SHEETBBHEET 2.

Witnesses: Inventor R 0567*! fine-fines W By Witty iUNiTED STATESPatented April 25, 1905.

PATENT UEETCE.

SOUND-PRODUCING DEVICE.

SPECIFICATION forming part of Letters Patent No. 787,984, dated April25, 1905.

Application filed November 6,1903 Serial No. 180,090.

Be it known that I, ROBERT HOPE-JONES, a subject of the King of GreatBritain, and a resident of l lartford, in the county of Hartforl amlState of Connecticut, have invented certain new and useful Improvementsin Sound-Producing Devices, of which the following is a full, clear, andexact specification.

This invention relates to improvements in fluid-pressure devices forproducing rapid vibrations for various purposes, including theproduction of sound in connection with organs, sirens, and other soundinstruments.

The vibrating apparatus comprises a chambered piston and itscoi'iperating cylinder, the meeting walls of which are provided withperforations or ports for the admission of the pressure fluid from thepressure-chamber to the receiving-chamber. There are two or more sets ofthese perforations which by the vibrations of the cylinder are carriedalternately into and out of coincidence, and thus successively andrapidly interrupt the [low of the pressure fluid to thereceivingchamber. In the embodiment of this invention shown anddescribed herein it is employed with a resonating chamber or trumpetconnected with the receiving-ch11mber into which the air or other fluidadmitted through one of the said sets of perforations, herein designatedthe speaking-ports, is directed by a succession of puffs in approximatecoincidence with the vibrations of the piston In my United States PatentNo. 702,557 is described a device of this general class combined with anadjunctive or supplemental vibrating engine, the piston of which isreciprocated in both directions by a volume of air which is divertedfrom the sound-producing device. In the present invention thesupplemental engine is dispensed with, and

a portion of the same volume of air which is admitted to thereceiving-chatmber is also utilized to drive the piston in one directioninstead of opposing the piston for a portion of the time, as in theformer device, thus avoiding the necessity for the employment of aseparate supply of air of higher pressure or the employment of aseparate or enlarged purely the driving or motive functions of thedevice. The invention also comprises improvements in the form andarrangement of the parts, whereby greater simplicity, lightness,compactness, and inexpensiveness of construction are secured.

\Vhile this invention may be adapted for use in connection with manysound-producing instruments, it is here shown in connection with thepipe of an organ using compressed air as motive power.

Figure l of the drawings is a side view in section of this improveddevice and shows the piston approximately at the lower end ofitsstrolce, the s [tion beingtaken through the line 1 to 3 of Fig. 2.Fig. 2 is a plan view of the device, the sound-board or top of theairchest being omitted. Fig. 3 is a side view in section, similar toFig. 1, but with the piston shown in its uppermost position. Fig. 4 is aplan view in section on the line 4 4 of Fig. 3. Figs. 5, 6, 7, and 8show modified forms of the cylinder and piston constructed from tubing.Fig. 5 is a plan view of the piston; and Fig. 6 is a side view partly insection, the section being taken through the line 6 of Fig. Figs. 7 andS are similar plan and side views of the cylinder, the section of thelatter view being taken through the line 8 of Fig. 7.

The souml-board 21, upon which this device rests aml which is usuallyadapted to receive a number of these devices of the different pitchesrequired, forms the top wall of an air-reservoir or wind-chest, in whicha pressure of air is maintained. The pressurechamber 23 is inclosed bythe walls 24: and supported by the feet 25 and 26, the space between thefeet being open to the atmosphere. Communication between thepressure-chamber 23 and the wind-chest below the sounding-board 21. ishad by means of the opening 22 in the sound-board and the opening 29 inthe foot or base 26 of the pressurechamber. The cylinder 33 is providedwith flanges 34 and 35, which fit corresponding openings formed in theupper and lower walls of the chamber, the cylinder being supported bymeans of the straps or buttons 32. The

cylinder and piston for performing what are 1 joints, which have to bemade air-tight, are

provided with packing 19 in the customary way.

In this device the speaking function and the engine function are bothperformed by a cylinder 33 of uniform bore throughout in co operationwith a simple piston 41 of uniform diameter throughout fitting the boreof the cylinder. The wall of the cylinder 33 is perforated by a numberof circumferential ports comprising the speaking-ports 37, theengineport 36, and the exhaust-port 38, the cylinder being, in effect,composed of a series of rings connected together by the longitudinalribs 39 on the outside of the rings. The speaking-ports 37, which alsoserve as engineports for the downward movement of the piston, and theport 36, which serves as the engine-port for the upward movement of thepiston, all open into the pressure-chamber 23, while the exhaust-port 38opens into the space '30, being therefore in direct communication withthe outer atmosphere. The bottom of the cylinder is shown to be closedby a plug 40; but it may obviously be closed by a screw-cap or by anyother well-known form of closure.

The piston 41 is fitted to slide easily in the bore of the cylinder 33,and its interior is di vided by a diaphragm or partition 47 into twoopen-ended tubular chambers 42 and 43. The peripheral wall of the pistonis perforated similar to that of the cylinder by a corresponding numberof circumferential ports, the form of the piston being therefore, ineffect, made up of a series of rings united by the vertical ribs 46 onthe inside of the rings. The open upper end of the cylinder forms anoutlet for the pressure admitted from the sup ply-chamber 23 through thespeaking ports or passages 37 and 44. That outlet may lead directly tothe open air or to or through any desired apparatus with which thisdevice may be employed. In the arrangement herein shown the outletcommunicates with a resonator or trumpet 50 through the throat 49.

Secured to the upper wall 27 of the pressure-chamber is the base 51,which supports the resonator 50, the opening in the bottom of the latterbeing directly over the open end of the pistonchamber 42 and practicallyforming a continuation thereof. The combined area of the openingsthrough the speaking-ports is usually made somewhat greater than thearea of the throat 49, leading to the resonator, so that the act ofopening the speaking-ports admits a volume of air to thereceiving-chamber in excess of that required for the resonator, thisexcess being utilized for moving the piston downwardly.

The engine port 45 for communicating with the port 36 opens into thelower chamber 43 below the partition 47, while the speaking-ports 44open into the upper chamber 42, which in this construction forms the larer 6 5 portion of the receivingchamber. The re ative position of theseports is such that when the piston is in its lower position, as shown inFig. 1, the lower or exhaust port 38 of the cylinder is closed by thewall of the piston, while the port 36 communicates with the port 45,leading to the chamber 43. The upper or speaking ports 37 and 44 of thecylinder and piston, respectively, are closed, the ports of each memberbeing closed by the adjacent wall of the other member. While in thisposition the air entering the ports 36 and 45 moves the piston towardits upper position of Fig. 3.

When the piston 41 is in its upper position, the speaking-ports 37 and44 are in coincidence, while the piston-chamber 42 is in communicationwith the pressure-chamber 23. The piston-chamber 43 is at the same timein direct communication with the atmosphere through the uncovering ofthe exhaust-port 38, the port 36 being meanwhile closed by the wall ofthe piston 41. In this position of the piston the air entering throughthe coinciding speaking-ports 37 and 44 causes a compression to takeplace in the air in the lower end of the resonator and reacts downwardlyto carry the piston 41 to its lower position of Fig. 1.

The normal stroke of the piston 41 is seen by comparison of Figs. 1 and3, which respectively represent the piston approximately at the lowerand upper ends of its stroke. The ports of one member are in practicepreferably made somewhat wider than the corresponding ports of the othermember, in the present case the ports of the piston being shown somewhatwider than the ports of the cylinder, so as to afford latitude forslight overrunning of the stroke after the ports reach full openingwithout reducing the opening again, so as to throttle the flow of theair, which should have free ingress until it has cushioned, stopped, andreversed the move ment of the piston. The extent to which the ports ofone member are widened should be sufiicient to allow for all suchvariations in the stroke of the piston; but in order to positivelyprevent accidental overrun of the upward movement the base 51 is made tooverlie the piston and prevent it going above the position shown in Fig.3. The plug 40 at the lower end of the piston similarly serves toprevent overrun of the piston at the lower end of its stroke. In normaloperation, however, there will be a clearance at both ends of the strokesimilar to that shown in Fig. 1 be tween the plug 40 and the piston, thestops being provided merely to prevent the piston passing by and closingthe port-openings. The plug 40 serves also to support the piston whenthe device is not in operation with the ports 36 and 45 in openposition, so as to start automatically upon admitting the pressure tothe pressure-chamber 23.

In the operation of this mechanism the air under pressure enters thechamber L3 through the passages 22 and 29 and passing through the ports36 and 45 enters the chamber 43, where by means of the pressure exertedon the under side of the partition 47 it raises the piston 41 until itswall closes the port 36. The continued expansion of the air and themomentum of the piston carries it upward until the speaking ports 37 and44 are in communication, at which time pressure will be exerted on theupper side of the partition J, as the lower portion' of the column ofair in the resonator 50 will be momentarily compressed when thesespeaking-ports are opened. Thus the speaking-ports, which admit the airto the resonator, serve also as engine-ports tor the downstroke ot' thepiston. is the piston moves downward the air in the chamber 45 passes tothe outer atmosphere through the exhaustport 38, which has beenuncovered by the lifting of the piston, the ports 37 and 38 are oncemore closed, the port 36 is reopened, and the cycle of movement repeatsitself, thus keeping the piston in a state of rapid vibration. Thesevibrations of the piston will produce musical sounds without any furtheradjuncts; but I prefer to confine it with a tone producing or regulatingdevice or resonator, as is shown herein. The length and size of theresonator will within certain limits determine the periodicity of thevibrations, as it is evident that the column of air therein willregulate the motion of the piston and will tend to bring its periodicityof movement into substantial accordance with the natural periodicity ofthe resonator. It the length of the column of air in the resonator beslightly increased, the action of the piston will be slightly re tarded,while it the length be reduced the ac tion of the piston will beaccelerated. This construction of the device enables the respectiveparts to be made of the material. best suited to them. The cylinder andpiston are preferably made of metal. The tubular construction of onediameter throughout permits the parts to be both light and strong. Thissimple form of these parts also greatly facilitates the proportioningand adjusting of the dimensions and weight of the piston to suit thedesired pitch of the sound to be produced. The weight of the piston maybe further modified by making it of lighter metalas. for example,aluminiumwhere a light weight is desired.

Any desired number of these devices may be arranged side by side inrows, as in the case of an organ-stop, controlled by valves or slides,which enables the entire row or any individual member of the row to bethrown into or out of operation, according to wellknown methods ot organconstruction and arrangement.

In Figs. 5 and 6 a modified form of piston is shown made from tubing ofsuitable material. The ports 56 and 57 in this case are not entirelycircumferential, but are made by a number 01 saw-cuts, leaving thevertical strips 58, which serve to hold the remaining segments 59together. A partition 60 divides the piston into the upper and lowerchambers 61 and (32, respectively, as before.

The modified form of cylinder 65 (shown in Figs. 7 and S) mayalso beconstructed of tubing and is designed to cooperate with the piston 55,(shown in Figs. 5 and 6,) the circum- 'l'erential ports 66, 67, and 68being made similar to those of the piston by a series of saw-cutsseparated by the joining-strips 69. The cylinder 65 may be securedwithin the pressurechamber 23 by making the holes in the top 27 and thebottom 28 of a suitable diameter and forming the plug a0 so that it willbe long enough to rest on the soundboard 21 and at the same time engagethe lower edge of the cylinder 65, so as to prevent any possible endmovement in that direction, the resonator-base 51 serving, as before, asimilar purpose at the upper end.

I claim as my invention 1. In soLind-producing device, the combinationwith a resonator and a chamber for a supply of fluid under pressure, ofa cylinder provided with a series of speaking-ports, and an engine-port,a tubular piston working in the cylinder, and having a partitiondividing its interior space into two chambers, one of which is providedwith a series of speaking-ports corresponding with those of thecylinder, the other chamber being provided with an engine-port,corresponding to that ol. the cylinder.

2. In a sound-producing device, the combination with a resonator and achamber for a supply of fluid under pressure, of a cylinder having abore of uniform diameter throughout, a tubular piston mounted to slidein said bore and having its interior space divided into two chambersopening at opposite ends of the piston, one of the said chambers beingprovided with speaking-ports, and the other chamber with an engine-port,and the cylinder being provided with a corresponding series of speakingand engine ports.

3. In a sound-producing device, the combination with a resonator and achamber for a supply of fluid under pressure, a cylinder provided with aseries of speaking-ports and with an engine-port, a tubular piston o'tuniform diameter fitting the bore of the cylinder and having itsinterior space divided by a partition into two chambers opening at theopposite end of the piston, one of the chambers being provided with aseries of speakingports corresponding with those of the cylinder, andthe other chamber being provided with an engine port communicating withthat of the cylinder when the speaking-ports are out of communication.

&

4. In a sound-producing device, the com.- bination with a chamber for asupply of fluid under pressure, of a cylinder provided with a series ofspeaking-ports and an engine-port communicating with the said chamber, atubular piston provided with separated chambers, a series ofspeaking-ports, and an en gine-port corresponding with those of thecylinder, and, opening into the separate chambers of the piston, theengine-ports being arranged to communicate when the piston is at thelower end of the stroke, and the speaking-ports to communicate at theupper end of the stroke.

5. In a sound-producing device, the com bination with a resonator, and achamber for a supply of fluid under pressure, of a cylinder providedwith a series of ports, a piston working in the said cylinder, andprovided with a corresponding series of ports, the cylinder and thepiston constituting a fluidpressure engine, the ports of one seriesbeing wider than those of the other series to permit slight overrun ofthe piston-stroke, without reducing the area of the passage through.

6. In a sound-producing device, the combination with a resonator, and achamber for a supply of fluid under pressure, of a cylinder providedwith a series of ports, a piston working in the said cylinder, andprovided with a corresponding series of ports, the cylinder and thepiston constituting a fluid-pressure engine, the ports of one seriesbeing wider than those of the other series to permit slight overrun ofthe piston-stroke, without reducing the area of the passage through, andstops at the ends of the piston for preventing it from exceeding thepredetermined amount of overrun of its stroke.

7. In a sound-producing device, the com bination with a resonator, andwith a cham her for a supply of fluid under pressure, of a cylinderprovided with a series of speakingports and with an engine-portcommunictiang between the said chamber and the interior of the cylinder,a tubular piston of uniform diameter mounted to slide in the said cylin-

